Photo from www.glowingpets.com
Local authorities have said they will be releasing 20 million fish – silver and green carp – to combat the overwhelming pollution that runs rampant in Taihu Lake near Suzhou, our next door neighbor in China’s eastern Jiangsu province. Crazy? Maybe not.
While the pollution in this lake has come hand in hand with the fast paced economic and industrial development experienced over the last few decades, the excess of blue-green algae is also a by-product of the untreated sewage. Just last year, this became a problem when it contaminated the water supply. Enter pollution-fighting fish.
These types of algae eating fish have been used successfully in the past to clean up Taihu and other lakes; the government now hopes to mirror this success. Carp are known for their ability to consume up to 50 kilograms of algae and other plankton in their lifetime, while only putting on 1 kilogram of weight. Jealous, ladies?
But an environmental risk assessment report published in 2005 for the U.S. Fish and Wildlife Service says that things aren’t so black and white. The authors concluded that the use of silver carp is sometimes unsuccessful at alleviating the proliferation in algae. Certain species of blue-green algae can pass through the gut of silver carp unharmed, and even pick up nutrients on the way. Thus, in some cases blue-green algae blooms have been aggravated by the presence of these fish. Also, some algae has been shown to produce more toxins in the presence of silver carp, enough so that the fish themselves become hazardous to eat.
Which means we’ll get tainted water and toxic fish. Mmmm, and just in time for dinner.